Probability Calculator
Calculate probability of events
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How to Use Probability Calculator
Select type
Choose single event, union, conditional, or Bayes.
Enter values
Enter event probabilities.
Calculate
See probability result with formula.
Why Choose AllTools Probability Calculator?
- ✓ Single event
- ✓ Union P(A∪B)
- ✓ Conditional P(A|B)
- ✓ Bayes theorem
- ✓ Formula display
- ✓ No data stored
Why Use This Tool
- ★ Instant calculations with no server round-trip
- ★ Completely free with no usage limits
- ★ No account or registration required
- ★ Accurate results using standard mathematical formulas
- ★ Works on any device including phones and tablets
Related Resources
Frequently Asked Questions
What is Bayes theorem? ▼
P(A|B) = P(B|A) × P(A) / P(B). It calculates the probability of A given that B has occurred.
Does it support conditional probability? ▼
Yes. Calculate P(A|B) using Bayes theorem or direct conditional probability formulas.
Does this work on mobile? ▼
Yes. All AllTools calculators are fully responsive and work on phones and tablets.
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